Vaned pumps and motors



Dec. 3, 1963 J. (ARMAK 3,112,709

' -VANED PUMPS AND MOTORS Filed Juli; 14. 1961 6 Sheets-Sheet 1 Mill 'Julm Yawn fawmflmmwm Dec. 3, 1963 J. YARMAK VANED PUMPS AND MOTORS 6 Sheets-Sheet 2 Filed July 14, 1961 6 ML, wys

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6 Sheets-Sheet 5 Filed July 14. 1961 mdI United States Patent 3,112,7tl9 VAVED PUMPS AND Euiius Yarmala, Swadlincole, England, assiguor to 6on1 industry (Patents) Limited, London, England Filed .luly 14, 196i, Ser. No. 124,13tl 4 mantis. (Cl. ltl3l3e This invention relates to vaned pumps and motors, that is to pumps and motors of the type comprising a stator, a rotor co-operating with the said stator to form at least two liquid chambers, at least two inlets and outlets defined by the said stator, each of said inlets and outlets being in communication with a liquid chamber, and one or more vanes arranged to sweep the chambers and displace liquid therefrom upon rotation of the rotor.

The main diiliculties experienced with vane type apparatus limiting their efiiciency and application, lies in balancing the vanes, adjusting displacement, and above all sealing and preventing working fluid from escape and leakage, mainly in slots where vanes are fitted, and at the ends of the rotor; as these parts must have free movement they cannot be fitted too tightly and are subjected to wear which leads to increased gaps and leakages.

An object of the invention is to overcome these dithculties.

The main object of the invention is to provide a vane pump or motor of the type referred to above in which tigh ess of all contacts among moving parts acting to retain fluid under pressure (vanes, rotor, guide ways, stator) are achieved by self sealing means adapted to compensate any increased clearance between the parts caused by Wear, thus ensuring continuously high efficiency of the apparatus, even at the highest operating pressures,

as the tightness increases with pressure and is independent rom wear.

Another object of the invention is to provide means and arrangement for admission of oil to the inner ends of the vanes, in slots, for balancing fluid pressure during outward and inward movements of the vanes, not axially through port in end plates as is usual in well known constructions, but radially across the length of the vanes, through grooves provided in the vanes, and thus eliminating restriction in the relative length of the rotor. For the same capacity of apparatus the rotor can be longer but of small diameter which is advantageous in many respects.

The above described main objects of the invention, as well as other objects and features of the new construction will readily be understood from the detailed description of an example embodying the invention in a balanced type vane pump of adjustable displacement, provided with ball type rectifying valves arrangement for delivery in one direction only independent from direction of rotation and having hydraulic or screw means for displacement adjustment.

The detailed description is given hereafter with reference to the accompanying drawings in which:

FEGURE l is a side elevation partly in section along line 1-1 of FIGURE 2 to show details of rotor and ball valves,

FIGURE 2 is a cross section along irregular line 22 of FIGURE 1, 1

FIGURE 3 is a plan view of the pump,

FIGURE 4 is a view similar to that shown in FIGURE 2 but showing an alternative screw and hand wheel arrangement for adjustment of the pump displacement,

FIGURE 5 is an enlarged scale side view of vane in rotor slot showing springs,

FIGURE 6 is section along line 6-6 of FIGURE 5,

FIGURE 7 is a cross-section along line 7-7 of El URE 5, and

Fatented Dec. 3, 15 53 FIGURE 8 is similar to FIGURE 7 but shows vanes and springs when sliding along inclined portion of guide way.

The balanced type vane pump of adjustable displacement comprises a rotor =11, keyed on shaft 12, supported on roller bearing 13, and driven by gear 14. The rotor 11 is provided with a number (in this case twelve) of radial slots 15, in each of which two vanes 16 and 17 are slidably fitted. In each slot a single or double leaf spring 18 are provided which abut by their outer bent surface on inner side of slots 15 and thrust by their ends on both vanes 16 and 17 near their ends.

The rotor 11 is located and enclosed in bore 19 (EIG- URE 2) of stator 29 by means of two end covers 21 and 22 dowelled and bolted to the stator by means of fitted bolts 23. The length of the rotor 11 and vanes 16 and i7, is the same as that of stator 20 with some small running clearances at each end. Between the stator 26 rotor 11 and vanes 16 and 1:7, and each end cover 21 and 22., wearing and sealing diaphragm plates 24 and 25 (FIGURE 1) are clamped tight by the same bolts 23.

It may be seen on drawings (FIGURE 2) that a cam track for vanes 16 and 17 is of an oval shape coming close to the rotor It at both sides 26 and 27 and providing room for the vane projection at top 28 and bottom 29.

Four bores 3t 31, 32 and 33 are provided for flow of hydraulic fluid. Thus, for example, by clockwise rotation of the rotor, hydraulic fluid will be taken from bores 33 and 33 and delivered to bores 31 and 32 correspondingly. Bores 3t) and 33 are communicated together in pipe 34 via flanges 35 and 36, bolted to the stator 2t) and curved pipes 37 and 38, similarly bores 31 and 32 are communicated together in pipe 39 via flanges 40 and 41 and curved pipes 42 and 43 (FIGURE 3). The bottom end of each pipe 34 and 39 (FIGURE 1) is provided with non-return suction valve 44 or 45 of the ball type, situated below oil level 4-6. Each top end of the same pipes are provided with non eturn delivery valves 47 and of the same ball type. Delivery ends of both pipes 34 and 39 communicate together inside tlan-ge 45 immediately after valves 47 and 48, to delivery into one delivery pipe 53.

Now it may be understood that by either direction of rotation of the rotor 11 hydraulic fluid will be sucked in from below level either through valve 44 and delivered through valve 4%, or alternatively by opposite direction of rotation fluid will be sucked in through valve 45 and delivered through valve 4-7 to the same outlet pipe 5%. The arrangement serves thus to rectify direction of working rluid flow independent of direction of pump rotation.

For adjustment of the pump displacement, the surface of the cam track for vanes it; and 17 is provided with two movable separator members 51 and 52 (FIGURE 2) having their stem portions 53 and 54 slidably fitted in slots of stator 2d. Fluid sealing packings 55 fitted in grooves of the stator are provided to prevent fluid leakage. Middle cylindrical surface 56 (part of 5), 57 (part of 52), which are angularly slightly larger than the angular spacing of each two adjacent vanes to provide overlap, form a separator between low and high pressure zones of the pump. Forked portions 5?, 59, so and d1 overlap tangentially corresponding projections 62, as, 6 2- and of the stator 29 to provide a changeable shape but continuous and smooth cam track for the vanes.

Both separators 5i and 52 can he slid radially in relation to the rotor 11 so as to adjust allowed projection of the vanes and in this Way to alter displacement or" the pump from zero to a maximum. By simultaneous and equal adjustment or" both separators 5i and 52 the shape of the oval cam track is maintained symmetrical about vertical plane V-V and horizontal plane H-H in all positions which is required to maintain balance of hydraulic forces acting radially on the rotor.

The adjustment of separators 51 and 52 may be affected hydraulically by admission of oil under pressure through pipes 66 and 67 into cylinders 63 and f? bolted to stator ill and provided inside the pistons 74 and 7 1 acting on thrust members 72 and 73, thus forcing the separators 51 and 52 towards the rotor 11, reducing allowable projections of vanes 16 and 17, and decreasing displacement of pump as required. To slide separators 51 and 52 out so as to increase displacement compression springs 74 (FIG- URE 2) and 75 (FIGURE 1) are provided. The springs will pull separators 51 and 52 by means of bolts '76 as long as oil is allowed to escape from cylinders as and 69*.

Alternative arrangement for hand adjustment is shown in FIGURE 4, where a right and left hand threaded spindle 77, is rotatably attached to the stator 2i} by means of two plates 78 and 79 and washers 8 and 81, preventing axial movement of the spindle are provided. The spindle 77 is fitted with handwheel 82 to impart rotation in nuts 83 and 84 restrained from rotation by Clamps and 86 and acting through spherical washers 87 and 89 or ends 9!) and 9d of levers. The second ends 92. and 93 of the levers are attached to blocks 94 and 95' by pivot pins 96 and d7. Pivoting of the lever ends 90 and 91 (extreme positions 98 and $9 shown chain dotted) will impart movement through balls 19:2 and lilil to the thrust members 72 and 73 and to the separators 5'1 and 52 in a similar way to that described above in the case of hydraulic adjustment.

The whole pump as a unit is supported by means of bracket 1'54 bolted by bolts 16-5 to the pump and bolts 16. 5 to the rigid member 1G7.

One novel and characteristic feature of the construction distinguishing the invention is the arrangement of springs and vanes in slots. As described previously, there are provided two vanes 16 and 17 in each slot id of the rotor 11. The radially outer edges 1&8 and id? (FIG-t URES 7 and 8) of the vanes are rounded to slide easily on the cam track surrounding the rotor. The radially inner edges 11% and 111 are chamfered at approximately so as to provide inclined planes for wedging action. The ends of spring 18 thrusting on the inclined planes lift and 111 produce side forces by the wedging effect pressing each vane against adjacent side wall of slot, leaving gap 112 between vanes. ElGURE 7 indicates position when both vanes follow cylindrical portion of the cam track and project to the same amount, and FIG- URE 8 shows position when vanes follow inclined portion of the cam track and the vane 17 is projecting more than the vane 16. In this case spring 18 slides slightly to one side of slot, but the wedg-ing action on the inclined planes 116 and 111 remains the same, both vanes are pressed against the cam track and against side walls of slot, thus separating and sealing continuously space 113 from space 114 in spite of gap 112, between vanes, and radial clearance 19 (FIGURE 2) between rotor 11 and stator 2%. It may be appreciated that even very considerable amount of Wear of slots 15 and vanes as well as stator and the cam track for vanes can be taken up without imparting the self sealing effect described above. Pressure of working fluid acting on one side of projecting ends of vanes will, of course, tilt the vanes in slot in one direction or other, but the acting pressure will only increase the self sealing effect in direct proportion to the pressure.

To admit working fluid to flow freely into and out of slots 15 behind vanes during their reciprocating movement, there are provided several (in this particular case four) recesses or wide grooves 1-15 and 116 (FIGURES 1 and 6) on faces of vanes 16 and 17, facing each other to communicate continuously outer and inner ends. Pressure at outer ends 108 and 1% (FIGURES 7 and 8), and inner ends 11% and 111 maintained always the same, thus balancing radial forces acting on vanes.

For self sealing effect at the ends of rotor, there are provided wearing and sealing diaphragms or plates, 24 and 25 (FTGURE l), of steel or other metal of a suitable thickness. The plates are clamped tight between stator 24 and end plates 21 and 22 correspondingly, and are provided each with four small holes 117 with seated balls 118 loaded by compression springs 119 forming thus four non-return valves in each plate admitting working fluid under pressure from either of four zones, 3h, 31, 32, 35 (FTGURE 2), inside the stator to space 12% and 121 (FE URE 1) between the end plates 21 and 22 and diaphragms or sealing plates 24 and 25, to prevent the fluid escape towards the shaft 12 there are provided 0 rings 12?. and 123. The fluid under pressure trapped in the narrow space 12% and 12-1, provides a cushion pressing and deflecting the diaphragm or sealing plates 24 and 25 against the end of rotor 11, separators 51, 5' 2 and vanes 16 and 17 taking up any gaps and sealing, and preventing working fluid from leakage and escape. The sealing force always will be in direct proportion to working pressure and a considerable amount of wear can be taken up without imparting the self sealing effect.

The construction of the pump as described above, as well as the arrangement of vanes in each slot, is quite symmetrical, therefore, the pump can be run in either direction of rotation.

Description of a variable delivery pump or motor is given above, but it may be well understood that a constant delivery pump or motor, having very similar, but simpler construction in that they have a cam track for vanes of a constant shape will, of course, fall inside the scope of the invention.

1 claim:

1. in a rotary engine of the vane type including a stator, a rotor rotatably housed in said stator and having a plurality of vane slots spaced around its periphery, a pair of vanes disposed face to face and reciprocable in each slot, the opposite side edges of each vane being in sliding and sealing engagement with two spaced parallel walls formed in said stator and resilient means adapted to urge each pair of vanes outwardly whereby the radially outer edge of each vane is maintained in sliding contact with a cam track provided in said stator, the improvement which comprises a pair of oppositely directed bevelled faces formed at the junctions of the confronting surfaces and the radially inner edges of each pair of vanes, each bevelled face extending between the said parallel walls, said resilient means being adapted to act on said bevelled faces to urge the vanes outwardly and to urge the constituent vanes of a pair in-opposite directions into sealing engagement with the immediately adjacent slot walls.

2. An improved rotary engine of the vane type as claimed in claim 1, wherein said resilient means is in the form of an elongated strip of spring steel disposed at the base of each slot and arranged longitudinally to the slot walls, said strip being of arcuate shape and having its convex central portion in contact with the base of said slot, and its end portions interposed between and acting on said bevelled faces.

3. An improved rotary engine of the vane type as claimed in claim 2, wherein said strip has a transverse width less than the distance separating the said slot walls, and is adapted to slide bodily between the said slot walls to accommodate variations in the locations of the vanes constituting a'pair relative to one another as they mainin said liquid chamber is applied to said pressure chamher to deflect said diaphragm into Contact with the appertaming sides of said vanes and said rotor.

Referemes Qited in the file of this patent UNITED STATES PATENTS 342,721 Wood May 25, 1886 1,119,699 Houser Dec. 1, 1914 1,573,683 Diffinger Feb. 16, 1926 1,846,557 Imshenetsky Feb. 23, 1932 2,238,062 Kendrick Apr. 15, 1941 2,318,346 Wakefield May 4, 1943 Rosen Jan. 15, Roth et a1. May 13, Talbot July 1, Hicks Sept. 19, Ferris Mar. 16, Wilcox Mar. 17, Bilas Nov. 22, Henning et a1 Jan. 17, Frazer Mar. 14,

FOREEGN PATENTS France Nov. 2, 

1. IN A ROTARY ENGINE OF THE VANE TYPE INCLUDING A STATOR, A ROTOR ROTATABLY HOUSED IN SAID STATOR AND HAVING A PLURALITY OF VANE SLOTS SPACED AROUND ITS PERIPHERY, A PAIR OF VANES DISPOSED FACE TO FACE AND RECIPROCABLE IN EACH SLOT, THE OPPOSITE SIDE EDGES OF EACH VANE BEING IN SLIDING AND SEALING ENGAGEMENT WITH TWO SPACED PARALLEL WALLS FORMED IN SAID STATOR AND RESILIENT MEANS ADAPTED TO URGE EACH PAIR OF VANES OUTWARDLY WHEREBY THE RADIALLY OUTER EDGE OF EACH VANE IS MAINTAINED IN SLIDING CONTACT WITH A CAM TRACK PROVIDED IN SAID STATOR, THE IMPROVEMENT WHICH COMPRISES A PAIR OF OPPOSITELY DIRECTED BEVELLED FACES FORMED AT THE JUNCTIONS OF THE CONFRONTING SURFACES AND THE RADIALLY INNER EDGES OF EACH PAIR OF VANES, EACH BEVELLED FACE EXTENDING BETWEEN THE SAID PARALLEL WALLS, SAID RESILIENT MEANS BEING ADAPTED TO ACT ON SAID BEVELLED FACES TO URGE THE VANES OUTWARDLY AND TO URGE THE CONSTITUENT VANES OF A PAIR IN OPPOSITE DIRECTIONS INTO SEALING ENGAGEMENT WITH THE IMMEDIATELY ADJACENT SLOT WALLS. 